1. Field of the Invention
This invention relates to a new base for cosmetic detergents which contains alkyl ether sulfate surfactants, and which exhibits particular flow properties based on the presence of special fatty acid alkanolamides and of sodium and magnesium ions.
2. Statement of Related Art
In addition to good cleaning power, cosmetic detergent bases suitable for the production of liquid hair and body shampoos have to show good foaming power and good compatibility with the skin and mucous membrane. In addition, it is a considerable advantage if a detergent base of this type remains fluid and pumpable, even at high concentrations, but does not become too thinly liquid after dilution to the in-use concentration or which may still be effectively thickened, so that the shampoo does not run through the fingers like water in use.
It was known that alkyl ether sulfates, particularly in the form of their magnesium salts, are distinguished by particularly good compatibility with the skin and mucous membrane. This applies especially to ether sulfates having a high degree of ethoxylation. Unfortunately, however, the foaming power and the viscosity and thickenability of the dilute solutions by electrolytes decreases with increasing degree of ethoxylation. It is also known that the viscosity and thickenability of dilute solutions of surfactants can be increased with fatty acid alkanolamides. However, in solutions of relatively high concentration of the type commonly and economically required for the detergent bases, an addition of fatty acid alkanolamides leads readily to gel formation and to loss of pumpability.